Has it been a perfect campaign? Of course not. But nobody else has been savaged in the MSM like Mitt has been. And, to date, nobody else has had his record, or decades old statements, scrutinized in the same fashion. Being the early frontrunner with the biggest target on him, Mitt's had to wage a two-front battle against his opponents and the MSM. He's held up pretty well.
Also, we could argue that Iowa and NH were not true tests of his strength. In Iowa we saw an unprecedented number of first-time evangelical voters turn out and in NH we saw democrats and independents vote for McCain (it's unclear whether they actually support McCain or were just attempting to weaken Romney). In one of the most conservative states, Wyoming, Mitt won by a large margin.
Given the fact that it's an open primary in MI, I don't think MI is do or die for Mitt either. People are not stupid (well, not all of the people) and they can see what is going on with the cross-over voting.
I love the argument that Mitt is a good candidate because he is unable to get Independent’s votes.
I want someone who can get independent votes, it’s the only way we can win in November.